Federal and private guards were disciplined, but officials with the National Nuclear Security Administration and Wackenhut Services Inc. downplayed the findings as paperwork slip-ups instead of performance flaws and said weapons inventory procedures had been stepped up.

"We don't believe this indicates a systematic problem," said Al Stotts, a National Nuclear Security Administration spokesman in Albuquerque, N.M. The NNSA oversees the Office of Secure Transportation, which moves conventional and nuclear weapons, weapons components and radioactive material around the country.

"Clearly, there was some sloppiness that needed to be cleaned up," said Jim Long, president and chief executive of Wackenhut, based in Palm Beach Gardens, Fla. "That's what we did and that's what the government did."

The nine-month investigation was triggered after New Mexico-based guards improperly took government and personal handguns to a training exercise at the Nevada Test Site in October 2003.

The eight-page report released Wednesday found the violations included a federal guard who brought a personal gun to the Test Site to be fixed by a Wackenhut employee - an apparent violation of ethical conduct rules.

It found accounting controls lacking for two of 19 government handguns moved in June 2001 from an armory at Fort Chaffee, Ark., to the NNSA's National Training Center in Albuquerque.

It also traced two government-owned handguns signed out by a Wackenhut employee from a NNSA armory in Albuquerque in October 2003. Two other Wackenhut employees handled the guns before one gave them to his wife at a truck stop outside Albuquerque early Nov. 1, 2003. She stored them overnight in her car at home.

"He told us that he was concerned about transporting the handguns onto Kirtland Air Force Base without the proper custody documentation," said the report, which noted inadequate record-keeping exposed the weapons to theft, loss or misuse.

Long called the change-of-hands "not normal," but cast it as an attempt by seasoned guards to ensure the weapon remained safe until it could be turned in the next day.

"When you've got 10,000 people working for you, every once in a while some violate policy," the Wackenhut chief added. "When they do, you take appropriate action."

Long and Stotts declined to identify the guards involved or what discipline they received. But they said adherence to existing handgun inventory, storage and transport regulations had been tightened in response to the report.

Authorities were sure the guns were not used for illegal purposes, they said.

"We're confident we know where the weapons were at that time," Stotts said. "It's the procedures that weren't followed."

An official with the Service Employees International Union, which has been fighting Wackenhut over unionization and safety issues nationwide, cast the report as the latest in a series of troubling problems.

"This is developing into a real pattern with Wackenhut," said Andrew McDonald, a Los Angeles-based union spokesman.

McDonald noted that a federal inspector general's report last year accused Wackenhut of cheating on performance drills at the Energy Department's facility in Oak Ridge, Tenn. In September, a live bullet was discharged and struck a refrigerator during training at Oak Ridge. No one was hurt.

At the Nevada Test Site, security was beefed up recently after guards failed to stop a mock terrorist attack on a bunker built to safeguard weapons-grade nuclear material.

Wednesday's report did not focus on Wackenhut employees based at the Test Site, where Wackenhut's security contract is up for renewal in March. The company has provided security at the vast federal reservation north of Las Vegas since 1965.

The test site contract is worth about $35 million annually, Long said, about twice the contract for security at the Office of Secure Transportation in Albuquerque.